1. Technical Field
The embodiments herein generally relate to sports equipment, and more particularly to golf club shaft grips.
2. Description of the Related Art
Installing and replacing golf club grips remains a time-consuming, cumbersome, tedious, and antiquated process. Most conventional golf club grips come in one of two forms. One type is an elongated flat strip of material which is helically wrapped around the golf club shaft with the ends of the strips secured by metallic fasteners, windings, glued or seated into plastic nipples, etc. The edges of the wrapped strip may be abutted, overlapped, interlocked or bound by wire or windings. Flat helically-wound elongated strips were the industry standard prior to the development of the other type of grip; the single-piece slip-on type tubular sleeve grip. However, a major problem common to helically wound strip type grips is the tendency of the side edges of the spiral to fray or curl from stretching, frictional contact with the golf bag and other clubs and exposure to perspiration, water, wind, and sun. Other problems include unraveling grips due to breakage of fasteners, windings, or deterioration of adhesives. Additionally, contrary to claims otherwise, a high level of skill is required to satisfactorily and consistently align the strip while wrapping. Even more problematic is the use of glues, tapes, and other adhesives to secure the elongated strip to the golf club shaft. Once the adhesive is applied it is difficult, if not impossible, to adjust the strip once the wrapping process has begun without weakening the essential bond between grip and golf club shaft from repeated readjustments. The difficulties attendant to helical strip type grips begged a solution: the conventional and ubiquitous single piece slip-on elastomer tubular sleeve was proposed.
Single piece slip-on elastomer sleeve type grips solved the curling edge problem. However, they generally made the process of installation more difficult by several magnitudes. Materials and tools typically required to replace and install a single piece slip-on elastomer sleeve include bench vice, shaft protector, solvent, sharp knife, double faced tape, rags, spray bottle, solvent recover tray, etc. Prior to installing a single piece slip-on elastomer tubular sleeve type grip, the installer must generally first remove the old grip, its underlying adhesive, then thoroughly clean the golf club shaft. The installer then applies new adhesive; most likely double faced peel-away tape to keep the sleeve grip in position once it is applied onto the club shaft. As the tape is sticky, the installer pours or spays a solvent over the tape, shaft, and inside surface of the sleeve grip to make them sufficiently slick to enable the installer to force the grip sleeve over the open end of the golf club shaft. The commitment of time and material coupled with the enhanced skill level required to satisfactorily complete the grip installation process is usually beyond the patience and skill level of the average golfer. Moreover, the freshly grip golf club must sit several hours to overnight before the adhesive dries sufficiently to permit use.
The conventional solutions generally do not provide a simple, quick, reliable, and comprehensive remedy to the problems attendant to spirally wrapped strips and single piece slip-on grips. Repeated attempts have been made to address the issues of time, skill, and material requirements of installing golf clubs grips including the need of adhesives, fasteners, or windings to secure the grip to golf club shaft. The U.S. Patents and Publications cited below describe various technologies that have advanced golf equipment manufacturing, and while each reference was useful at the time they were created and for the specific purpose for which they were intended, the golf industry has evolved so quickly that many of these useful techniques are no longer readily applicable for today's modern golf industry and game. The current inventors are not denigrating the cited references, but are merely identifying observations with respect to the corresponding technologies and their uses in today's practical applications.
For example, U.S. Pat. No. 2,671,660 issued to Goodwin, the complete disclosure of which, in its entirety is herein incorporated by reference, discloses a flat and substantially planar resilient flanged strip attached to an integral cap. The cap is positioned over an open end of the club and the strip is stretched and wrapped around golf club shaft utilizing the strip's frictional properties against the club shaft to avoid the need for adhesives to keep the grip in place. The abutting and overlapping flanged edges are used as a guide to assist the installer during wrapping. An additional winding/wire may be wrapped around the strip to apply additional pressure to the golf club shaft.
Goodwin generally proposes a remedy for grip/shaft adhesive failures and a simplification of the task of wrapping and aligning the strip around the golf club shaft. However, the dimensional properties and sole reliance on frictional characteristics of the material may not adequately work with current state of the art golf club shafts. For example, as the strip is stretched and wrapped, the outer and inner surfaces of the strip begin experiencing disparate shear forces resulting in cracking and failure of the top surface of the strip. Additionally, the stretched outer surfaces and edges of the strip tend to plasticize resulting in concaving of the top surface, curling of edges, loss of tensile strength and thereby loss of the wrap's “grip” on the golf club shaft. Furthermore, the winding generally fails to offset the above described forces.
U.S. Pat. No. 2,836,420 issued to Lamkin, the complete disclosure of which, in its entirety is herein incorporated by reference, discloses a locking mechanism stitching together two strips with preformed resilient curls. The stitched strips are spirally wrapped around the shaft with resilient curls overlapping, and attempt to inhibit the curling of the edges. The Lamkin patent uses leather material to attempt to resist curling. However, in the many years since the Lamkin's patent was issued, the use of leather has proven to be an infective material for this purpose due to material stretching caused by use. Additionally, the Lamkin patent does not describe how the strip is secured to the golf club shaft. Furthermore, the abutting edge joint in the Lamkin patent is not water tight in practice. Finally, the skill level required to wrap Lamkin's strip is generally high.
U.S. Pat. No. 1,556,781 issued to Gjorup, the complete disclosure of which, in its entirety is herein incorporated by reference, attempted to improve upon strip type grips by using a stretched elastic tape held in place by the frictional properties of the elastic, and optionally reinforced by adhesive applied to the underside of the tape. However, exclusive reliance on the frictional properties of the elastic material to secure the strip to shaft has proven to be less than desirable. Additionally, the optional adhesive described in the Gjorup patent generally does not overcome the tensile forces of the stressed strip grip, especially in modern day golf shafts.
U.S. Pat. No. 4,174,109 issued to Gaiser, the complete disclosure of which, in its entirety is herein incorporated by reference, discloses a flat strip with one open edge the other edge containing adhesive tape. The tape is spirally wrapped around the handle with the tape covering the seam. Additionally, no adhesive is used to secure the tape to the handle.
U.S. Pat. No. 5,895,329 issued to Huang, the complete disclosure of which, in its entirety is herein incorporated by reference, discloses a cap and elongated strip with reinforced recessed side edges and peel-away tape attached to the underside of the strip. The strip is spirally wrapped around the golf club shaft with peel-away adhesive securing the strip to the shaft. The strip is further secured at the bottom with finishing tape and the top by affixing a cap. The issue of adhesive is not addressed in the Huang patent; only the ease of installation and curling of side edges of the strip. The Huang patent further addresses the issue of ease of installation touting the general nature of the spirally wrapped type of grip. The Huang patent further describes compressing the edges with a heated platen to inhibit the curling of the strip edges, and suggests that adhesive may be applied while wrapping to help bond the abutting edges.
In practice, the device provided in the Huang patent does not generally factor in the impact that the natural expansion and contraction from use and exposure to climate has on the compressed edges of the strip, which may lead to curling or fraying of the strip in practice. The adhesive on the underside of the strip tends to limit re-adjustments during wrapping and, in practice, tends to undermine the objective of ease of installation, notwithstanding the difficulty of applying adhesive to abutting edges while wrapping. In later patents Huang resorted to wrapping the strip around an underlisting sleeve first then applying as a unitary slip-on.
U.S. Pat. No. 6,971,959 issued to Lu, the complete disclosure of which, in its entirety is herein incorporated by reference, discloses a locking mechanism that inhibits the curling of the edge by locking the upper and lower edges. However, both the Gaiser and Lu patents do not generally address the issue of securing a strip to a handle suggesting adhesive is applied to the shaft. The Lu patent bonds the edges of the interlocking edges with adhesive, but unfortunately there is no teaching of how to insure a snug fit of the wrap upon initial installation.
The concept of replacing adhesive with tensile stressed elastic has been used in the past. A viable wrap style alternative to the unitary sleeve type grip to avoid the need for adhesive to secure the grip to the shaft must generally: first, provide a simple and user-friendly method of quickly wrapping strip around shaft; second, stabilize the tensile forces allowing them to continue their adhesive work without risk of unraveling and plasticization of material; and third, the ability to quickly remove the grip without the mess of slip-ons. To date, no solution provides a grip addressing all three of the above. A wrap style grip offers the best hope for convenience and ease of installation. However, in order to be commercially viable, the wrap around must equal the slip-on in quality and durability without the fear of shear failure, edge fraying, etc. In the mistaken belief that edge fraying was the paramount issue in the early pursuit of an improved golf club grip, which had been resolved through single piece, most advances in golf grips have been confined to materials only. The issue of convenience has been generally ignored.
Wrap style to a limited extent, and slip-ons nearly exclusively have been made of one form or another of vulcanized rubber. Since the 1930s the properties of silicone rubber has attracted golf grip manufactures. Silicone is durable, resists hardening or cracking, water resistant, flexible, soft shock absorbent, and can be produced in a wide range of colors unlike carbon-based vulcanized rubber, which are all qualities advantageous to golf club grips. Under extreme temperature, the silicone rubber's tensile strength, elongation, and tear resistance is superior to most conventional rubber materials. However, wet silicone can be slippery and has a higher specific gravity (heavier) than traditional single piece slip-on tubular sleeve type grips.
U.S. Pat. No. 4,552,713 issued to Cavicchioli, the complete disclosure of which, in its entirety is herein incorporated by reference, addressed the slippery nature of silicone in handgrips through a process of buffering the surface of the cured product and adding texturizing material. U.S. Pat. No. 5,686,158 issued to Gibbon, the complete disclosure of which, in its entirety is herein incorporated by reference, addressed the specific gravity (weight) issue by adding various material fillers in attempt to add strength while reducing weight. U.S. Patent Application Publication No. 2008/0305883 published to Cameron, the complete disclosure of which, in its entirety is herein incorporated by reference, discloses a silicone rubber grip. U.S. Pat. No. 5,216,069 issued to Kobori and U.S. Pat. No. 5,807,507 issued to Hirano, the complete disclosures of which, in their entireties are herein incorporated by reference, describe silicone elastomers having trace elements of boron.